Electrical conduit piping systems (also called enclosed raceway systems herein) are used to carry electrical wiring for power and/or communication. An electrical system (also called a cabling system herein) is one of many major systems in a facility (e.g., an industrial facility, a commercial building, a power plant). An electrical system is typically broad reaching, with electrical cables running throughout the facility. In some locations in a facility, a relatively large number of cables are run in a common area. In such a case, cables are laid in cable trays. In other locations in a facility, such as where specific electrical devices are located, a relatively small number of cables are run in a particular enclosed raceway within an enclosed raceway system. A facility often has a large number of enclosed raceways that make up an enclosed raceway system. An enclosed raceway can be rigid and/or flexible.
Enclosed raceways are sometimes run proximate to mechanical and plumbing systems of a facility. An enclosed raceway is often installed along a unique path, having one or more bends (e.g., 90° bends, 45° bends) and straight segments along the length of the enclosed raceway. As such, the path along which an enclosed raceway is installed is flexible. The flexible path of an enclosed raceway is needed to accommodate pre-existing objects (e.g., beams, plumbing, HVAC hardware, wall corners) in a facility. Enclosed raceways are often among the last components of an electrical system to be installed, and so there are likely a number of pre-existing objects around which an enclosed raceway must navigate. Consequently, the electrical enclosed raceways can require a lot of time and material to assemble.
Enclosed raceways provide protection to enclosed cables from impact, moisture, and chemical vapors. As such, conduit can be used to protect cables from being crushed, which can result in a fault condition. Rigid conduit is made in fixed lengths, and so a person (usually an electrician) installing rigid conduit as part of a enclosed raceway may have to perform a number of tasks with respect to the rigid conduit and associated fittings. For example, the installer may have to cut a length of conduit to size, shape a conduit pipe according to a particular curvature required based on the path to be followed, etch mating threads into the conduit, and connect the conduit with one or more fittings to accommodate the path of the enclosed raceway.
In an enclosed raceway system, conduit pipe can be joined to another component (e.g., another conduit pipe, a connector, a junction box, a motor control center, a switchgear cabinet, a control cabinet) using fittings. Such fittings can provide a connection and/or a change in direction. Failure to provide proper joints can cause discontinuity in the enclosed raceway system. Conduit pipe in such cases can be joined using mating threads. Even if a conduit pipe has mating threads disposed on each end, when a conduit pipe is cut to size, mating threads must be etched into the end of the conduit pipe. This process can be messy (leaving, for example, metal shavings, and oil stains) and time consuming. In addition, when conduit pipes are joined by mating threads in a hazardous or explosion-proof application, a flame path formed by the mating threads can be compromised by burrs that result from etching the mating threads into the conduit. The burrs can also damage cable, especially as the cable is being pulled in a cabling system.